The present invention relates to an improved centrifugal pump for household appliances such as washing machines, dishwashers and the like.
More in particular, the present invention relates to an improved pump to be used in an electrical household appliance, of the type comprising a pump body having a cylindrical chamber containing a permanent magnet rotor.
The electric part of the motor is entirely external to this structure, not being affected in any instance by the liquid.
Known types of pumps thus structured have problems related in particular to the fact that the permanent magnet rotor attracts, and becomes covered with, any metallic dust carried by the pumped liquid.
This dust, once caught by the permanent magnet of the rotor, can no longer detach therefrom, constituting therefore a dangerous jamming and wear element.
Besides this, a permanent magnet pump can start indifferently in one direction or the other, for this reason it is provided that the impeller be not rigidly associated with the motor shaft and the connection be, for a first angle, free and therefore with no mechanical resistance.
This may entail knockings and noises due to the interference of the impeller driving element which, after a certain angle, interferes with said impeller, causing its movement.